<?php

namespace App\Core;

class Request
{
    private array $get;
    private array $post;
    private array $server;
    private array $files;
    private array $cookies;
    private ?array $json = null;
    private array $routeParams = [];

    public function __construct()
    {
        $this->get = $_GET;
        $this->post = $_POST;
        $this->server = $_SERVER;
        $this->files = $_FILES;
        $this->cookies = $_COOKIE;
    }

    /**
     * Get request path without query string.
     */
    public function getPath(): string
    {
        $uri = $this->server['REQUEST_URI'] ?? '/';
        $position = strpos($uri, '?');
        if ($position === false) {
            return $uri;
        }
        return substr($uri, 0, $position);
    }

    /**
     * Get request HTTP method (e.g., GET, POST, PUT, DELETE).
     */
    public function getMethod(): string
    {
        return strtoupper($this->server['REQUEST_METHOD'] ?? 'GET');
    }

    public function isGet(): bool
    {
        return $this->getMethod() === 'GET';
    }

    public function isPost(): bool
    {
        return $this->getMethod() === 'POST';
    }

    public function isPut(): bool
    {
        return $this->getMethod() === 'PUT';
    }

    public function isDelete(): bool
    {
        return $this->getMethod() === 'DELETE';
    }

    /**
     * Set route parameters (extracted by Router).
     */
    public function setRouteParams(array $params): void
    {
        $this->routeParams = $params;
    }

    /**
     * Get route parameters or specific key.
     */
    public function getRouteParams(): array
    {
        return $this->routeParams;
    }

    public function routeParam(string $key, mixed $default = null): mixed
    {
        return $this->routeParams[$key] ?? $default;
    }

    /**
     * Fetch GET parameter.
     */
    public function get(string $key, mixed $default = null): mixed
    {
        return $this->get[$key] ?? $default;
    }

    /**
     * Fetch POST parameter.
     */
    public function post(string $key, mixed $default = null): mixed
    {
        return $this->post[$key] ?? $default;
    }

    /**
     * Fetch all request parameters parsed.
     */
    public function getBody(): array
    {
        if ($this->isJson()) {
            return $this->getJsonBody();
        }

        $body = [];
        if ($this->isGet()) {
            foreach ($this->get as $key => $value) {
                $body[$key] = filter_input(INPUT_GET, $key, FILTER_DEFAULT);
            }
        }
        if ($this->isPost()) {
            foreach ($this->post as $key => $value) {
                $body[$key] = filter_input(INPUT_POST, $key, FILTER_DEFAULT);
            }
        }
        return $body;
    }

    /**
     * Check if request is JSON.
     */
    public function isJson(): bool
    {
        $contentType = $this->server['CONTENT_TYPE'] ?? $this->server['HTTP_CONTENT_TYPE'] ?? '';
        return str_contains($contentType, 'application/json');
    }

    /**
     * Parse raw JSON request payload.
     */
    public function getJsonBody(): array
    {
        if ($this->json === null) {
            $rawInput = file_get_contents('php://input');
            $this->json = json_decode($rawInput, true) ?? [];
        }
        return $this->json;
    }

    /**
     * Get a specific input value (works for GET, POST, and JSON).
     */
    public function input(string $key, mixed $default = null): mixed
    {
        $body = $this->getBody();
        return $body[$key] ?? $default;
    }

    /**
     * Get all request headers.
     */
    public function getHeaders(): array
    {
        $headers = [];
        foreach ($this->server as $key => $value) {
            if (str_starts_with($key, 'HTTP_')) {
                $name = str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($key, 5)))));
                $headers[$name] = $value;
            } elseif ($key === 'CONTENT_TYPE') {
                $headers['Content-Type'] = $value;
            } elseif ($key === 'CONTENT_LENGTH') {
                $headers['Content-Length'] = $value;
            }
        }
        return $headers;
    }

    /**
     * Get specific request header.
     */
    public function getHeader(string $name, ?string $default = null): ?string
    {
        $headers = $this->getHeaders();
        // Match case-insensitively
        foreach ($headers as $key => $val) {
            if (strtolower($key) === strtolower($name)) {
                return $val;
            }
        }
        return $default;
    }

    /**
     * Get Client IP address.
     */
    public function getIp(): string
    {
        return $this->server['HTTP_CLIENT_IP'] 
            ?? $this->server['HTTP_X_FORWARDED_FOR'] 
            ?? $this->server['REMOTE_ADDR'] 
            ?? '127.0.0.1';
    }

    /**
     * Get User Agent.
     */
    public function getUserAgent(): string
    {
        return $this->server['HTTP_USER_AGENT'] ?? 'Unknown';
    }

    /**
     * Get uploaded file array.
     */
    public function file(string $key): ?array
    {
        return $this->files[$key] ?? null;
    }
}